Is it time for a standard 3D printer spool size?

The short answer is yes; yes it is. But not everyone, including some of the leading companies in the market, agrees.

Since their origin about a decade ago, desktop 3D printers have for the most part not been built with the filament spool in mind. As long as the spool sits close enough to the printer that the filament that wraps around it can easily find its way in, it is deemed good enough. I’ve used printers that had a simple hook on the back to hold a spool and others that had no hook at all, requiring users to just leave the spool on the table or build a custom stand. With a 3D printer, it’s easy to build your own custom-size hook, after all.

A gMax 3D printer with different sizes of spools. Photo by Signe Brewster.

The emerging generation of desktop 3D printers is gorgeous. The spool is no longer a side thought; instead, it’s designed right into the printer.

The upcoming Pirate3D Buccaneer 3D printer has a filament spool integrated into its top. Photo courtesy of Pirate3D.

Aside from just looking nice, a lot of these printers with integrated spools tend to jam less. You don’t have to babysit the spool to make sure it is turning nicely and feeding enough filament into the printer. The filament is less likely to twist at odd angles and snap.

But while filament has become somewhat standardized into two sizes (1.75 mm and 3 mm), spools still come in a crazy amount of sizes. 3D printer makers can’t design their printer to beautifully integrate a spool unless they’re willing to cut down on users’ choices.

RepRap users like the idea

A prominent member of the RepRap community put out a call this week for the industry to agree upon a standard spool size. Richard Horne, better known as RichRap, published a blog post describing what he sees as the biggest problems with current spool design.

Along with their size, he described how the methods manufacturers use to wrap filament can be a major problem that can lead to failed print jobs. He also noted that print quality can change as a printer works its way through a spool, as the amount of strength required to pull in filament changes.

He pointed out that many types of spools were developed with different industries in mind. Horne suggested a few spool design ideas in the blog post, but he is also soliciting ideas in the RepRap forum.

A RepRap 3D printer. Photo by Signe Brewster

This is a no-brainer for smaller startups that make filament specifically for 3D printers, and I am sure they will be quick to adapt to any standard that is adopted. Large filament manufacturers will be more difficult to convince, because it would require them to make different spools for different industries. But as they begin receiving more and more orders for 3D printing, it’s possible that they’ll shift their spool design to please the growing ranks of printer owners.

But any kind of standard spool will likely be restricted to 3D printers built by individuals or companies still clinging to the movement’s open source roots. Proprietary filaments and spools are appearing all over this year as, like with 2D printers, there’s a lot of money to be made from selling overpriced plastic to consumers. Profit-driven 3D printer companies would likely go to great lengths to keep standard-size spools out of their printers.

But companies are not so sure

A poll of five different desktop 3D printer makers brought mixed thoughts on developing a standardized spool. Andrew Rutter, founder and CTO of Type A Machines, which has built its reputation on supporting users who modify its printers, said his company would enthusiastically integrate standardized spools into its printers. Afinia, Pirate3D and Solidoodle were more skeptical.

Joseph Scott, a spokesperson for Afinia, said that the company’s printers are already compatible with most spool sizes. If not, a custom adapter can easily be printed.

Solidoodle sells a custom size of spool that CEO Sam Cervantes said was specifically developed to work with the company’s printers. While Solidoodle printers are compatible with most spools, Cervantes said most users gravitate toward using Solidoodle-branded filament.

A wall of Solidoodle 3D printers. Photo by Signe Brewster.

“Since not all printers are alike and many printers use different feeding technologies, the performance of one spool may vary greatly from one printer model to another,” Cervantes said.

He also questioned whether a standard size of spool could accommodate filaments that differ in size, friction, stiffness and material without damaging some types of filament or using a wastefully large spool.

Pirate3D management engineer Evgeny Lazarenko said proprietary spools and filament have an important role: They ensure people use compatible, high-quality filament, which protects their printer from damage. Co-founder and chief designer You Jun Tsang added he would be more interested in seeing filament standardized for quality. Pirate3D’s upcoming Buccaneer printer will use custom cartridges as spools, but they are refillable with any brand of filament. The company encourages users to use Pirate3D branded filament.

The Buccaneer 3D printer. Photo courtesy of Pirate3D

“Currently, different suppliers use widely varying methods of lactic-acid processing, and their factory operating conditions like humidity and temperature are often uncontrolled,” Tsang said. “It seems to me that most suppliers just want to make a quick-buck from unwary consumers, as such they throw quality out of the window.”

MakerBot, perhaps the one company that could make the greatest impact on the movement for a standardized spool, did not respond.